I cannot connect to WhatsApp!

see Unknown under your Account expiration
(To check, go to: WhatsApp > tap on the three dots at the bottom right > settings > account);

have problem updating your profile or status or favorites list.

The most common reason is that your phone is not connected to the internet.

Please try these steps

Confirm you are using the latest version of WhatsApp Messenger from the Marketplace.

Make sure that you have a data plan on your carrier's network or a Wi-Fi connection with a working internet access.IMPORTANT: To use WhatsApp on a Windows Phone, it is important to have a data plan. Devices that are Wi-Fi only can encounter problems.

Make sure the signal strength for Wi-Fi or data network is good and that the phone is connected to the network.

Reboot your phone.

I still cannot connect

Some carriers commonly have issues with WhatsApp on Windows Phone, even if it has worked before on other platforms. If websites and other apps are working but WhatsApp cannot connect, it is possible that your network configuration does not permit the type of connections (socket or non-HTTP connections) necessary for WhatsApp.

Please check the following:

Check your carrier's Access Point Name (APN) settings. There may be a different APN for your carrier that allows non-HTTP connections like WhatsApp.

About WhatsApp

WhatsApp Messenger is a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for iPhone, BlackBerry, Windows Phone, Android and Nokia.